Testing Solubility in different pH's and salt concentrations for NMR. - (Jul/13/2011 )

Hi, I want to do some NMR on a protein sample and would like to test its solublity in different pH + salt concentrations without wasting a lot of sample. Does anyone know a protocol or paper?

Thanks.

-jerseysurfer66-

i asked our local nmr genius...

if you want to perform 13C nmr then you can use any aqueous buffer, just don't forget to subtract background.

1H nmr requires deuterated solvent.

-mdfenko-

jerseysurfer66 on Wed Jul 13 16:55:00 2011 said:

Hi, I want to do some NMR on a protein sample and would like to test its solublity in different pH + salt concentrations without wasting a lot of sample. Does anyone know a protocol or paper?

Thanks.

In 500ul of your sample, add one drop of acid of your buffer(or 10ul diluted HCL) and mesure pH, continue adding and measuring until seeing ppt. Do the same using a base of your buffer (or diluted NaOH) and a salt (NaCL). Record the amount of each reagents you added before seeing ppt. From the concentration of the salt stock solution, you should be able to calculate the final salt concentration in your sample.